Insulating supporting pin



y 29, 1934- c. L. PIERCE, JR 1,960,681

INSULATING SUPPORTING PIN Filed May 5, 1953 INVENTOR Patented May 29, 1934 UNITED STATES INSULATING SUPPORTING PIN Charles L. Peirce, Jr., Pittsburgh, Pa., assignor of one-half to Hubbard and Company, a corporation of Pennsylvania Application May 5, 1933, Serial No. 669,551

Claims.

This invention relates to insulator supporting pins of the type having a screw-threaded portion on which insulators having internally threaded cavities may be mounted.

An object of this invention is the provision of insulator pins that shall be simple in construction, easy to manufacture, and possess great strength, resiliency, and durability.

Another object of the invention is the provi- 10 sion of a yieldable thimble for insulator supporting pins of such form and construction that it may be secured to the pin without in any way weakening the pin.

A further object of the invention is the provision of a pin having a yieldable tapered shell or thimble for the reception of an insulator, that shall be so formed and secured to the pin standard that the taper will remain substantially constant when an insulator is being screwed thereon.

A still further object of the invention is the provision of an insulator supporting pin having a yieldable thimble secured lengthwise to the pin standard so that the thimble may distribute the strains imposed on the insulator over a substantial length of the standard and thereby avoid the concentration of stresses at a single point or section of such standard.

Other objects of the invention will, in part, be apparent, and will, in part, be obvious from the following description taken in conjunction with the accompanying drawing, in which:

Figure l is a View in side elevation of an insulator supporting pin arranged and constructed in accordance with one form of the invention;

Fig. 2 is a view in section through the thimble and pin standard, taken on line II-II of Figure 1;

Fig. 3 is a fragmentary View in side elevation of an insulator pin illustrating a modified form of thimble;

Fig. i is a view in section of the supporting pin taken on line IVIV of Fig. 3;

Figs. 5 and 6 respectively, are views in section of an insulator supporting pin taken on lines corresponding to lines IIII and IV-IV, illustrating a further modified form of thimble;

Fig. 7 is a fragmentary view in side elevation of an insulator pin provided with another modified form of thimble;

Fig. 8 is a View in section through the pin standard and thimble of Fig. 7 taken on line VIII-VIII thereof;

Fig. 9 is a fragmentary View in side elevation of a pin standard with the thimble removed;

Fig. 10 is a view in section of a modified form of thimble mounted on the pin standard of Fig. 9; and.

Fig, 11 is a fragmentary view in side elevation of an insulator pin embodying a still further modified form of the invention.

Throughout the specification and drawing, like reference characters indicate like parts.

With reference to Figs. 1 and 2 of the drawing, an insulator supporting pin 1 is shown that comprises a standard 2 formed from rod or bar stock and a yieldable thimble 3 that embraces the upper end of standard 2 and is secured thereto. The thimble is formed with helical grooves 4 that serve as screwthreads so that an insulator (not shown) having an internally threaded cavity may be threaded or screwed thereon.

The insulator supporting pin is of the type adapted to be mounted on cross arms (not shown) or other supports. For this reason, standard 2 is provided with a flange 5 at about its middle and screw threaded at its lower end so that when the lower portion of the standard is passed through a hole in the cross arm or support, the pin will be rigidly clamped to such support by flange 5 and a nut 6.

Standard 2 may be made as a steel forging and the portion thereof above flange 5 may be tapered and of slightly larger diameter than the lower portion so that the standard will have suflicient strength and rigidity where bending moments and stresses are most severe in service.

Thimble 3 may be formed in two sections 7 and 8 of pressed metal with the helical grooves or threads 4 pressed into the same.

The sections of the shell or thimble are each provided with an inwardly projecting rib 9 formed longitudinally thereof, adapted to be secured at diametrically opposite sides of the standard, as by welding. If the sections of the thimble are welded to the pin, the standard may be formed with lugs or projections which, when welding current is applied, fuse and weld to ribs 9.

By securing the thimble sections to the pin standard in this manner, the sections are positively secured to the standard throughout substantially the entire lengths thereof. For this reason, the load strains imposed on the thimble and the pin standard will be distributed throughout a substantial length of the standard, thereby avoiding the concentration of stresses at a single point or section of the pin standard.

It is preferred to so shape the thimble sections that, when they are secured in operative position on the pin standard, the thimble will be some- What oval in transverse section, and the adjacent longitudinal edges of the thimble sections spaced a substantial amount to allow the thimble to yield and to conform to the shape of the threaded cavity of the insulator and tightly grip the same.

The thimble illustrated in Fig. 1 is tapered, that is the major and minor axes thereof increase grad-- ually from top to bottom, and thereby conform to the shape of the threaded cavities of insulators, which as a general rule, are also tapered.

Since the longitudinal edges of the thimble sections are free to deflect or yield throughout the full length thereof, the taper oi the thimble will remain constant as the insulator is screwed thereon. This feature insures uniform gripping action between the thiinble and the threaded cavity of the insulator.

As may be seen by inspection of 2, the tl1im-- ble is spaced from the pin standard at all points except where the inwardly projecting ribs 9 thereof are secured to the standard. The thimble, while initially oval in section, becomes somewhat circular in section when an insulator is screwed thereon.

In order to limit the amount that the longitudinal edges of the thimble sections may deflect, each section may be provided with inwardly projecting lugs 10 adapted to bear against the body of the pin standard when such deflection exceeds a predetermined amount.

In Figs. '7 and 8, an insulator pin 11 is illus trated that comprises a standard 2 and thimble 12 formed of sections 13 and 14: similar to the thimble sections of the pin illustrated in Figs. 1 and 2. These sections differ from the thimble sections of Figs. 1 and 2 in that they are provided with slits at predetermined points along the longitudinal edges thereof to provide greater flexibility in the thinible. It occasionally happens that an insulator has rough spots in the threaded cavity which tend to bind on the thimhle. By pro viding the thimble with these slits, certain portions of the thimble may deflect more than others and if any rough spots are present in the threaded cavity of the insulator, the thimble will yield at the points in direct contact with such rough spots without yielding throughout the full length thereof, thereby insuring a more uniform gripping action between the thimble and the insulator.

In Figs. 3 and 4, a modified form of thinible is illustrate-cl. This thimble is made from a single piece of sheet metal and pressed into the desired shape. One side of the thimble has a slot 15 extending the full length thereof, and the opposite side is provided with an inwardly projecting rib 16 adapted to be welded to the pin standard.

The adjacent edges of the thimble formed by slot 15 may be provided with inwardly projecting flanges 17 adapted to rest on the pin standard and hold it centrally in place thereon. The thimble may be somewhat oval in shape and tapered like the thimble of Figs. 1 and 2, '7 and 8, and of larger diameter than the pin standard so that it will be spaced therefrom and free to yield or flex when an insulator is screwed thereon.

Since the thimble is secured on a line lengthwise of the pin standard and throughout substantially the full length of the thimble, the thimble is secured to the pin standard at the points where the stresses as transferred from the insulator to the pin standard are the greatest.

The thimble being initially oval in section and free to expand and contract throughout its full length, it will grip the insulator tightly as it is screwed thereon, and the taper of the thimble will remain substantially constant throughout its full length.

The thimble illustrated in Fi s. 3 and 4 may be provided with slits of the kind provided in the thimble of Figs. 7 and 8 and for the same purpose.

Instead of making the thimble in two compl mental parts or sections and welding each part along diametrically opposed lines as in Figs. 1 and 2, 7 and 8, the thimble may be made in two parts or sections 13 and 19, as in Fig. 5, and welded longitudinally of and on one side only of the pin standard. As illustrated a longitudinal edge of each thimble section is flanged inwardly as at 20 and 21. These flanges are lap welded to each other and to the pin standard; and the opposite longitudinal edges may be flanged inwardly as at 22 and 23 so as to slidably bear on the standard. A thimble so constructed is spaced from the pin standard at all points except along the weld and at the free edges thereof.

It preferred to make the thimble of Fig. 5 on a taper and to give it initially an oval shape in transverse section so that there may be substar a1 gripping action between the threads of an insulator when screwed thereon and the thinlble. Since one side of each of the thimble parts is free to move, the taper will be the same when an insulator in place thereon as it was initially.

In Fig. 6, a thinible formed of two similar sections 24 and is illustrated. This form of thimble is similar to the thiinble of Fig. 5, except that the inwardly projecting ribs 26 and 27 of the thimble sections are welded longitudinally of the pin standard on diametrically opposite sides thereof. The free edges of each section are so positioned that they tend to overlap ribs 26 and 27 when an insulator is threaded thereon. This thiinble in other respects, is similar to the thimbles above described, that is, the thimble is preferably initially oval in section, tapered from top to bottom to fit the taper of the threaded cavities of insula tors that may be mounted thereon, and spaced from the pin standard at all points except along the lines where the ribs 26 and 2'? are welded thereto.

By making the thilnble and pin standard as indicated in 9 and 13, the thimble may be :iformed in one piece and the inwardly projecting ril which in the other forms are welded to the pin, may be omitted. As shown, the upper end of the pin standard is formed with a longitudinal outwardly projecting rib 28 to which the bases of the thimble threads are welded. The thimble is also formed with a lengthwise slit 29 that permits the thimble to yield and grip the insulator when threaded thereon. The free edges of the thimble may be formed with inwardly projecting flanges 30 and 31 that bear against the pin standard and tend to hold the thimble central thereon. This thimble, like the other thimbles previously described, may be made initially oval in transverse section and tapered from top to bottom, and since the thimble is free to yield throughout its full length, the taper will be the same when an insulator is threaded thereon as it was initially.

In Fig. 11, a different form of insulator pin is shown. This form comprises a standard 32 made from bar stock, preferably round, and a thimble 33. Thimble 33 includes a threaded portion 34 and a skirt 35 the lower end of which terminates in a bell shaped base or flange 36. This base serves the same purpose as flange 5 of pin standard Thimble 33 may be formed as a single piece or stamping having a slit 36 extending the full length thereof, and secured on a line lengthwise of the standard in the same fashion as the thimbles of Figs. 4 and 10 are secured to their associated standards. Thimble 33 "may also be made in two pieces or sections and secured to the standard in accordance with the forms illustrated in Figs. 1, 2, 5, 6, 7 and 8.

From the description of the several forms of insulator supporting pins embodying the invention, it will be apparent that in each form, the thimble is spaced from the pin standard, is secured on a line or lines extending lengthwise of the standard and thimble, is designed for substantially constant taper, and is initially oval in transverse section so that, when an insulator is screwed thereon, the thimble yields and tends to become circular or round in section. Such yielding and change in form insures a tight, uniform fit or grip between the thimble and insulator.

Since the various thimbles are secured on a line or lines lengthwise of the pin standards, the stresses imposed on the thimbles are distributed throughout substantial lengths of the standards, instead of being concentrated at a single point or section. Furthermore thimbles formed and secured in this manner to the standards do not weaken the standards.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. An insulator supporting member comprising a standard having a threaded yieldable thimble secured thereto along a line extending lengthwise thereof, the thimble being spaced from the standard at all points except along the line of securement to the standard.

2. An insulator supporting member comprising a standard having a yieldable substantially constant taper thimble secured to the standard along a line extending substantially lengthwise thereof, said thimble having spiral grooves therein serving as screw threads on which an insulator having a threaded cavity may be screwed.

3. An insulator supporting member comprising a standard having a threaded yieldable thimble secured to the standard along a line extending lengthwise thereof, the thimble being initially oval in transverse section and spaced from the standard at all points except along the line of securement thereto.

4. An insulator supporting member comprising a standard and a yieldable sheet metal thimble having screw threads formed therein and adapted to embrace one end of the standard in spaced relation thereto, said thimble being slit longitudinally and provided with an inwardly projecting rib, formed lengthwise thereof, welded to the standard.

5. An insulator supporting member comprising a rod and a yieldable sheet metal thimble disposed about one end of the rod, said thimble being substantially oval in transverse section and having screw-threads formed therein, and an inwardly projecting rib formed lengthwise thereof, the rib of said shell being welded to the rod.

6. An insulator supporting pin comprising a standard and a pressed metal threaded thimble provided with a longitudinal opening on one side, said thimble being of larger diameter than the standard and secured thereto on a line lengthwise thereof.

'7. A threaded thimble for insulator supporting pins formed of pressed metal and provided with a lengthwise opening on one side and an inwardly projecting lengthwise rib adapted to be welded to a pin standard, so that when the rib is welded to the standard the thimble is spaced therefrom to allow the thimble to contract or expand when an insulator is screwed on or off the same.

8. An insulator supporting pin comprising a standard and a thimble comprising a shell formed with a longitudinal slit to render the same flexible, said shell having an upper portion provided with threads and a lower portion that terminates in a flange adapted to form a bearing, said shell being of larger diameter than the standard and secured thereto on a line lengthwise thereof for a portion of its length.

9. An insulator supporting member compris ing a standard having a yieldable threaded thimble embracing one end thereof, said thimble com prising complementary sections mounted with their adjacent edges in spaced relation, each section being secured lengthwise to the standard and spaced from the standard at substantially all points except where secured thereto.

10. An insulator supporting member comprising a standard having a yieldable threaded thimble embracing one end thereof, said thimble comprising complementary sections mounted. with their adjacent edges in spaced relation, each section having an inwardly projecting rib extending lengthwise thereof and welded to the standard. CHARLES L. PEIRCE, JR. 

